# NTSB WPR17LA157: Cirrus Design SR22, N754AP, Ogden, UT, July 15, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: July 14, 2017, 19:48 local (Jul 15, 2017, 01:48 UTC) - Place: Ogden, UT - Coordinates: 41.195556, -112.01305 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=41.1956&lon=-112.0131&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Western Pacific Region - Parties: Cirrus Aircraft, Continental Aerospace Technologies, Federal Aviation Administration - NTSB case key (mKey): 95612 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR17LA157 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/95612/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=95612 - Page: https://openairdocs.org/ntsb/WPR17LA157 ## Probable cause The failure of the No. 4 cylinder exhaust valve head, which resulted in a total loss of engine power due to oil starvation. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Engine (reciprocating): recip eng cyl section](https://openairdocs.org/ntsb-findings/01058530): Aircraft › Aircraft power plant · Failure (probable cause); cases with it: [Cirrus Design SR22, 6 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md?model=2130001), [All aircraft, 373 cases](https://openairdocs.org/ntsb-findings/01058530/cases.md) - [Fluids: oil](https://openairdocs.org/ntsb-findings/01071020): Aircraft › Fluids/misc hardware · Fluid level (probable cause); cases with it: [Cirrus Design SR22, 5 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md?model=2130001), [All aircraft, 174 cases](https://openairdocs.org/ntsb-findings/01071020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Powerplant sys/comp malf/fail](https://openairdocs.org/ntsb-events/340) (defining event); cases with it: [Cirrus Design SR22, 10 cases](https://openairdocs.org/ntsb-events/340/sequence.md?model=2130001), [All aircraft, 820 cases](https://openairdocs.org/ntsb-events/340/sequence.md) - [Approach-VFR pattern final: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cirrus Design SR22, 31 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2130001), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) ## Analysis According to the pilot, the personal cross-country flight was uneventful until he was established on the final approach about 7 miles from the destination airport. At that point, he heard a bang, felt a shudder from the engine, and noticed the airplane’s oil pressure decreasing. Shortly thereafter, the oil pressure indicated zero and the engine shut down. Unable to maintain altitude and too low to deploy the airplane’s parachute, the pilot decided to land on a nearby open field. During the landing sequence, the airplane’s left wing struck two wood posts, incurring substantial damage. Postaccident examination of the airplane’s engine revealed that the No. 4 cylinder exhaust valve head was separated from the valve stem, which destroyed the No. 4 piston causing oil to dump through the No. 4 cylinder’s exhaust valve area. The resulting oil starvation led to catastrophic engine failure. The reason for the failure of the No. 4 cylinder exhaust valve head could not be determined. ## Factual narrative On July 14, 2017, about 1948 mountain daylight time, a Cirrus Design Corp SR22 airplane, N754AP, sustained substantial damage when it was involved in an accident near Ogden, Utah. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to the pilot, he was established on the final approach, about 7 miles from Ogden-Hinckley Airport, Ogden, Utah, when he heard a loud bang then felt a shudder from the engine. Subsequently, the engine’s oil pressure decreased to zero and the engine shut down. At this point, having lost altitude and believing that he was too low to deploy the airplane’s parachute, the pilot initiated a forced landing to a nearby open field. During the landing sequence, the airplane’s left wing impacted two fence posts, resulting in substantial damage to the wing. Postaccident review of the airplane’s flight data (downloaded from the its primary flight and multifunction displays) revealed that, after leveling off at 12,900 ft, the airplane cruised at that altitude until 1925:00, when it started to descend. At 1942:48, The exhaust gas temperature (EGT) values for all the cylinders began to decrease rapidly. Between 1943:00 and 1944:00, the EGT values for the No. 2, 4, and 6 cylinders dropped below the valid range of the sensor input. At 1943:00, the rpm, manifold pressure, oil pressure, and fuel flow values all temporarily increased and, 1 second later, these values decreased. At 1943:06, the oil pressure began to rapidly decrease. At 1943:30, the oil pressure indicated 0 psi and did not recover before the landing in the field. Examination of the engine revealed no noticeable impact damage, but a large hole in the top of the crankcase between the Nos. 3 and 5 cylinders was observed. All engine accessories were attached to the engine. The oil sump was intact, and a large amount of metallic material had collected within the sump. The oil pickup screen had a large amount of metallic material on the screen. The oil pump was removed and examined, and no anomalies were noted. The oil filter remained securely attached and was undamaged. Removal of the oil filter found its internal pleats were contaminated with metallic material. Examination of the oil cooler found no anomalies. During removal of the cylinders, it was noted that the No. 4 cylinder’s exhaust valve head was separated from the valve stem and was located within the engine. The valve head sustained extensive damage consistent with repeated impact in the combustion chamber. Metallurgy examination of the valve head and stem revealed that they met hardness requirements. Several cracks were also observed on the outer edge of the valve stem; however, the valve body’s condition before the crack formation could not be determined due to the condition of the valve head and stem. Further examination revealed that the internal portion of the No. 4 cylinder sustained mechanical damage and the piston was destroyed fromthe valve head separation. The disassembly of the engine crankcase uncovered all the bearing supports. Examination of the supports revealed no signs of fretting or bearing shift. The Nos. 1, 2, and 3 bearings were intact, undamaged, and exhibited normal operating and lubrication signatures. The Nos. 4 and 5 bearings exhibited damage consistent with lubrication distress. The crankshaft displayed thermal damage signatures around the Nos. 5 and 6 connecting rod journals and the No. 4 main journal that were consistent with lubrication distress. ## Aircraft - Registration: [N754AP](https://openairdocs.org/aircraft/N754AP), registered now, S/N 2871 (OpenAirDocs) - Reported make and model: CIRRUS DESIGN CORP SR22 (NO SERIES) - Registry model: [Cirrus Design SR22](https://openairdocs.org/model/cirrus-design-sr22) (registry code 2130001) (OpenAirDocs) - Registry engine: [Continental IO-550-N](https://openairdocs.org/engine/continental-io-550-n) (registry code 17215, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2871 - Year built: 2007 - Airframe hours: 1480.5 - Engines: CONT MOTOR IO-550-N 310 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 28, 2017 - Departed: VGT, LAS VEGAS, NV - Destination: OGD, Ogden, UT - Airport: OGD, Ogden-Hinckley, runway 03, 8,103 × 150 ft, asphalt - Equipment: Electronic primary flight display, Satellite tracking device, Stall warning system, Airframe parachute, Auto-pilot, Data recorder, Electronic multifunction display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review November 22, 2015; seat: left; restraint: 4-point; flight hours: 1,395 total, 1,395 in this make and model, 1,302 as pilot in command, 42 in the last 90 days, 20 in the last 30 days, 2 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 27 knots, gusting 33 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F, dew point 43 °F - Altimeter: 30.14 inHg - Observed at: OGD, 5 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20170714023059A](https://openairdocs.org/incident/20170714023059A), Jul 14, 2017: Cirrus Design Corp SR22, Ogden, UT, Substantial damage. On long final about 1,500 AGL the pilot heard a bang and a shudder, pilot noticed the oil pressure was about 35 PSI but RPM was still at 2250 RPM. ATC asked… ## Docket (10 files) The files NTSB released with the investigation on January 28, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=95612. 54.8 MB in all. - Cockpit displays - specialist's factual report (item 1, PDF, 11 pages, 1.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11879075&FileExtension=pdf&FileName=Cockpit%20Displays%20-%20Specialist%27s%20Factual%20Report-Rel.pdf - Attachment 1 to cockpit displays - specialist's factual report (item 2, CSV, 38 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8624366&FileExtension=csv&FileName=Attachment%201%20to%20Cockpit%20Displays%20-%20Specialist%27s%20Factual%20Report-Rel.csv - Attachment 2 to cockpit displays - specialist's factual report (item 3, CSV, 115 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=8624023&FileExtension=csv&FileName=Attachment%202%20to%20Cockpit%20Displays%20-%20Specialist%27s%20Factual%20Report-Rel.csv - Metallurgical report (item 4, PDF, 4 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11870735&FileExtension=pdf&FileName=Metallurgical%20Report_Redacted-Rel.pdf - Record of email (item 5, PDF, 1 page, 119 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11783586&FileExtension=pdf&FileName=Record%20of%20Email%20WPR17LA157-Rel.pdf - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 6, PDF, 11 pages, 2.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11783416&FileExtension=pdf&FileName=NTSB%206120_Redacted-Rel.pdf - Airframe and engine examination report (item 7, PDF, 4 pages, 637 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11783524&FileExtension=pdf&FileName=WPR17LA157%20Airframe%20and%20Engine%20Examination-Rel.pdf - Continental motors engine examination report (item 8, PDF, 36 pages, 47.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11784020&FileExtension=pdf&FileName=17-048%20N754AP%20Engine%20Examination%20Report_Redacted-Rel.pdf - Statement of party representatives to NTSB investigation (item 9, PDF, 2 pages, 1.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11781476&FileExtension=pdf&FileName=Party%20Forms%20Final_Redacted-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 10, PDF, 1 page, 484 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=11783823&FileExtension=pdf&FileName=Wreckage%20Release%20Form_Redacted-Rel.pdf From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.